Friction shock-absorbing mechanism



June l1, l929- J. F. ocoNNQR FRICTKION SHOCK ABSORBING MECHANISM 3 Sheets-Sheet Original Filed Feb. 8, 1923 June ll, 1929.

J. F. OCONNOR FRICTION sHocK ABsoRBING MECHANISM original Filed Feb. 8, 1925 43 J// 7 WM 5 Sheets-Sheet 2 v| a I FLg Jy l 1 i j V/ //////7///// June-11, 1929.

J. F. O'CQNNOR FRICT'IONSHOCK ABSORBING MECHANISM original Filedpeb. 8, 192.3 3 sheets-sheet Patentes .time 11, i929.

EJETED STATES PATENT OFFICE.

JOHN F. OCONNOR, OF CHICAGO, ILLNO'IS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO W. H. MINER, INC., A CORPORATION OF DELAVARE.

FRICTION SHOGK-ABSORBING MECHANISM.

Application filed February 8, 1923, SeraI No. 617,695. Renewed November 19, 1928.

My invention relates to improvements in friction shock-absorbing mechanisms.

One obj ect of my invention is to provide a friction shock absorbing mechanism, more particularly adapted for railway draft riggings, wherein is obtained high capacity due to large frictional areas, and wherein a differential wedge action is made use of to assure quick and certain release of a plurality of friction plates.

Another object of the invention is to pro videl` a friction shock absorbing mechanism of the type referred to, wherein a preliminary action of the followers and the wedges l5 takes place, prior to the engagement of the ends of the friction plates by the followers,

' to permit easy release of the parts when the actuating pressure is removed.

A still further obj ect of the invention is to provide a friction shock absorbing mechanism of the intercalated friction 'plate type, including a plurality of wedges for transmit ing wedge pressure to the intercalated plates,rwherein the plates are subject to f transverse movementin addition. to relative longitudinal movement.

'Other objects of the invention will .more clearly appear from the description and claims hereinafter following.

Fig. l is a horizontal longitudinal. sectional view of a portion of a. draft rigging showing my improved shock absorbing mechanism in connection therewith. Fig. 2 is a vertical transverse sectional view, corresponding substa .ially to the line 2 2 of Fig. l. Fig. 3 is a. vertical longitudinal sectional view corresponding' substantially to the line 3-3 of Fig. 2. Fig. el is a detail side ele Yational view of one end of one of the friction plates. Figs. 5 and 6 are detail perspective views of an end and a central. wedge respectively, used in connection with my improved friction draft gear. Fig. 7 is a horizontal longitudinal sectional view similar 'to Fig. l, showing a modified form of the invention. And Fig. 8 is a vcrtica transverse sectional. view corresponding substantially to the line 8 8 of Fig. 7.

ln said drawings, lll-l0 indicate channel shaped center or draft sills, to the inner faces of which are secured front stop lugs ll and rear stop lugs l2. A portion of the draw-bai .l

own at lll, to which is attached arranged groups.

a hooded yoke v14. The shock absorbing mechanism proper, including front and rear follower casings, is disposed within the yoke lei and the movable parts of the draft rigging are supported by the detachablel saddle plate 15.

The embodiment of my improved friction draft gear shown in Figs. l to 6 inclusive, comprises, broadly, front and rearl follower casings A-A; friction plates B-B; pairs of front and rear end wedges C-C; a pair of central wedges DMD; tapering friction elements E E; an outer pair of combined wedge and spring follower caps F-F an inner pair of combined wedge and spring follower caps G-G; tandem arranged spring resistance elements Irl-H; and retainer bolt J.

The follower casings A are of similar construction, each being of substantially box like shape and comprising spaced horizontally extending upper and lower' walls 1- 'l6, vertically extending spaced side walls 17-17 and end walls 1,8. The end wall lS of the front and rear follower casings A coact respectively with the front stop lugs 11 and the rear stop lugs 12. The side walls 17 of each casing A are provided with interior, oppositely arranged friction surfaces 19, converging inwardly from the open end to the closed end of the easing. The casings vare normally spaced apart a proper distance,

so that, when the gear is fully compressed, the inner ends of the casings will abut, and 'the actuating force transmitted directly from one casing to the other.

The friction plates B are arranged within the casings A and comprise two oppositely As herein shown, the groups of plates B each comprise three plates and three plates 2G, the plates 25 and 2G being alternated, with a. plate 25 of each group arranged outermost and in Contact with the inner face of one of the tapering friction elements E. The plates Q'and 2G are of similar construction and as best shown in Fig. 4, each of the plates 25 is formed with upper and lower projections at one end thereof to provide alined upper and lower shoulders 257, for a purpose hereinafter described.

Arranged between each of the groups of friction plates B and the adjacent side walls 17 of the casings Agis a tapering friction element E. As clearly shown in Figs. l and 8 each of the tapering friction elements E is in the form of a rectangular plate 28 provided with an inner fiat friction surface 29 adapted to co-act with the outer friction surface of the outermost friction plate 25 of one of the groups of plates. The outer face of each tapering element E is oppositely inclined utwardly from the center' toward the opposite ends thereof, thereby providing oppositely extending surfaces 8l-8l slightly inclined with reference to the longitudinal axis of the shock absorbing mechanism. As clearly sho'wn in Fig. l, each of the surfaces 8l of the friction element E, co-acts with the corresponding inner friction surface 'i9 of one of the casings A and is arranged parallel thereto. As shown in 3 each plate E has the upper and lower edges cutaway at the center thereof to provide recesses 82 for a purpose hereinafter described.

The wedges C are four in number, and are arranged at opposite ends of the shock absorbing mechanism, one pair being adapted to co-act with cach follower casing. Each of the wedge blocks C is provided with an outer flat face 33, adapted to abut the inner face of the end wall 18 of the casing A, an inner wedge face 34 and a flat side face 85 adapted to engage with the innermost friction plate 26 of one of the groups of plates B. As clearly shown in Fig. 5, each of the wedge blocks C is reduced in height at the wedge end, by cutting away the upper and lower ends as indicated at 86.

The central wedge blocks D are of like construction and are arranged on opposite sides of the shock absorbing mechanism.

Each of the central wedge blocks D is provided with a pair of inwardly converging wedge faces 87 adapted to co-act with the inner pair of central wedge and spring follower caps G. As clearly shown in Fig. (i, each of the wedge blocks D is of triangular shaje and has the outer side thereof cut away to provide a fiat bearing face 88, and spaced nppei and lower flanges 89 having outer square ended portions 40, corresponding in size to the recesses 82 in the tapering friction elements E. The outer portions 40 of the upper and lower flanges 89 of the wedge blocks D are loosely received within the recesses formed in the tapering friction elements F, as clearly shown in Fig. 8, thereby connecting the wedges with the eiements E for relative lateral sliding movement thereto, with the fiat inner face 88 of each wedge D abutting the innermost friction plate 25 of one of the groups of plates B and the flanges straddling the group of plates.

The combined wedge and spring follower caps are four in number, comprising an outer pair F-F, and an inner pair (5e-G.

Each of the combined wedge and spring follower caps, as clearly shown in Fig. l, is provided with a counter-sunk axial bore 41 adapted to receive one end of one of the spring resistance elements H. At the outer end each of the spring caps is provided with a pair of converging wedge faces 42, the wedge faces 42 of the outer pair of caps F being adapted to cosact with the wedge faces 84 of the wedge blocks C, and the wedge faces 42 of the inner pair of caps G being adapted to co-act with the wedge faces 37 of the central wedges D. Each of the outer combined wedge and spring follower caps F is provided with pairs of upper and lower laterally extending lugs 43, on the opposite sides thereof, adapted to engage with the shoulders 27 of the friction plates B, the lugs 48 being vertically spaced apart the proper distance to loosely receive the plates B and the reduced ends of the wedges C therebetween.

The spring resistance elements H are arranged in tandem, each co-operating with an outer and inner combined wedge and spring followerl cap F and G respectively. Each of the spring resistance elements H comprises an outer, relatively heavy, coiled spring 44 adapted to abut the shoulders 45 formed by the counter bore 47 of the caps F and Gr, and an inner, relatively lighter, coiled spring 46 received in the counter bored portions 47 and adapted to abut the end walls of the combined wedge and spring follower caps F and G.

The shock absorbing mechanism is held under initial compression by the retainer bolt J passing through the inner springs 4G and alined recesses in the combined wedges and spring follower caps F and G, having one end thereof anchored to the rear follower casing A by means of the head 48 received within the hollow boss 49 projecting inwardly from the wall 18 of the rear casing A and having the other end thereof anchored to the front follower casing A by means of the nut 50 received within the hollow boss 51 projecting inwardly from the end wall 18 of the front follower casing A.

when the parts are in normal position as clearly shown in Fig. i, the outer combined wedges and spring caps F have the wedge faces thereof in engagement with the wedge faces of the wedge blocks C and are held in their extreme. outer position by the expansive force of the spring resistance elements H, with the lugs 48 in engagement with the shoulders 27 of the friction plates B. As shown in Fig. l the friction plates 25 and 26 are alternated and reversely arranged with the shoulders 27 of the friction plates 25 engaging the. lugs 4b' of the combined wedge and spring follower'cap F at the front end of the gear and the shoulders 27 of the plates engaging the lugs 48 of the combined wedge and spring follower cap F at the rear end of the gear, thereby holding the opposite ends of each set of plates and 26 slightly spaced from the adjacentend wall 18 of the corresponding follower casing A.

ln the operation of my improved shock absorbing mechanism, assuming that the front follower A is being moved rearwardly toward the rear follower during buff, a wedge action will be set up between the wedges (l and the combined wedge and spring follower' caps F, and between the central wedges D and the combined wedge and spring follower caps G, effecting a corresponding compression of the spring resistance elements H, whereupon the outer faces of the wedges C and D will be forced into tight engagement with the groups of' fric* tion plates B, thereby putting the friction plates and the tapering friction elements-E under pressure, and augmenting the frictional resistance between the saine. During' the initial inward movement of the follower A, due to the wedging action between the faces 19 of the front follower casing and the faces 3l of the tapering friction elements E and the wcdging action between the inner combined wedge and spring cap followers Gr and the central wedges DMD, which are connected to the tapering wedge friction elements E by the laterally projecting lugs 39, there will be a tendency for the tai ering friction elements E to move rearwardly with the front follower A. As there is a corresponding wedgingaction between the inner walls of the rear follower A and the tapering friction elements E, and between the central wedges D and the combined wedge and spring follower cap G associated with the rear follower casing, there will be a balancing tendency to prevent rearward movement of the tapering friction elements lil-Fl. Due to this balancing of frictional resistance tending to move the tapering frictional elements rearwardly and tending to oppose movement of the same, the latter will be moved rearwardly a distance equal to one-half the movement of the outer follower casing A. During this movement of the tapering friction elements E, there will be an equal bodily rearward movement of the friction plates B due to the clamping action of the wedges C, D and the friction element-s E, thereby maintaining the spacing between the ends of the two sets of plates and the end walls of the follower casings A constantly substantially equal as the followers approach the ends of the plates. During this inward move nent of the front follower A the lugs 4:3 on the caps F and the shoulders27 on the plates .B will be moved out of contact and the end walls 18 of the follower casings will gradually approach the endsof the respective sets of friction plates 25 and 26, until the same are engaged thereby and are moved therewith. Upon further movement of the front follower the friction plates 25 will. be moved therewith, relatively to friction plates 26 opposed by the frictional resistance therebetween due to the wedging action vof the mechanism. During the described operation of the mechanism, a differential wedge action will be set up. Due to the wedging action between the outwardly converging faces of the tapering friction elements El, there is effected a lateral inward bodily movement of the groups of friction plates B and a corresponding inward movement toward the axis of the gear of the wedges C and D causing the wedge faces thereof to move inwardly on the wedge faces of the combined wedge and spring caps F and Gr, effecting' an additional compression of the spring resistance elements H.

During the draft action of the shock absorbing mechanism, the operation is similar to that just described, the only difference being that the rear follower A is moved relatively to the front follower A.

Upon removing the pressure on the shock absorbing mechanism, the front and rear sets of wedge blocks C, together with the respective followers A, will be caused to move apart first by the expansion of the springs H, thus causing the release of the wedge mechanism and an immediate decrease `of the pressure on the friction plates, prior to any relative movement of the fric tion plates with reference to each other and with reference to the kelements E. During the outward movement of the wedges C and the combined wedge and spring follower caps F, the lugs lf3 on the latter will approach the shoulders 27 of the friction plates B, nally engaging therewith and restoring the friction plates to their original position with the free ends thereof slightly spaced from the inner faces of the walls 18 of the front and rea-r follower casings. The expansive action of the springs will also effect the centering of the tapered friction elements E through the action of the combined wedge and spring follower caps G and the central wedges D.

The modification shown in Figs. 7 and 8 comprises, broadly, front and rear follower casings A-A; friction plates BB; front and rear wedge blocks C--C; front and rear pairs of friction wedge shoes D-D; tapering friction elements E-E; kfront and rear spring followers F -F; spring resistance G and retaining bolt H.

In the modified form shown in Figs. 7 and 8, the front and rear follower casings A-A are of substantially the same construction as the follower casings A-A of the preferred embodiment, having horizontal top and bottom walls 11G, vertical side walls f 117, end walls 118 and inner opposed friction surfaces 119 converging inwardly `from the open end of each casing toward the end wall 118 thereof. Each of the casings A is also provided with an inwardly projecting hollow boss 1l9 on the end wall thereof. rlhe boss 149 of each casing is provided with an inner flat face 151 adapted to forni an abutnient for the corresponding wedge block C.

The friction plates B are of the saine construction as the friction plates i3 of the preferred embodiment of the invention, and are arranged in two groups, each group coniprising two sets of plates 125 and 126 rcspectively, similarly arranged to the plates 25 and 2G of the preferred forni of the invention.

rflic tapering friction elements E are interposed between the groups of friction plates and the inner friction surfaces 119 of the front and rear follower easings il. Each of the tapering` friction elements E is provided with a fla-t inner friction face 129 adapted to eo-act with the outer face of the outermost friction plate 126 of one of said groups, and a pair of outer friction faces 131 adapted to cosaet with the inner friction surfaces 119 of the front and rear follower easings respectively. The outer friction surfaces 131 of the tapering friction elements E are inclined to the a of the gear similarly to the corresponding friction surfaces o1 of the friction elements E of the preferred forni of the inventionj each extending parallel to the corresponding frietion surface 119 of one of the casings A.

rlhe wer ge bloclrs C are of like construction7 each being provided with a flat face 152 adapted to abut the face 151 of one of the bosses 14:9, and a. pair of inner wedge faces 158 adapted to (fo-act with a pair of friction wedge shoes D.

The friction wedge shoes D are four in nuniber, arranged in pairs, at the opposite ends of the shock absorbing mechanism, each pair eri-acting with the corresponding wedge bloclr C. Each of the friction wedge shoes D is provided with a` wedge face ll` adapted to cenet with one of the Wedge faces 153 of one of the wedge blocks C, an outer elongated fiat friction face adapted to co-aet with the innerniost friction plate 126 of one of the `groups of plates B, and a flat rear face 156 forming an abutinent for the spring follower ll". As clearly shown in 7, each of the wedge friction shoes C is in the forni of an elongated ineinber provded with a laterally projecting central portion forming` the wedge inenibcr proper whicn is provided with the wedge face 1541 and the follower abutment face 156.

The Afront and rear spring followers FF are of like construction, each being in the forni of a rectangular plate 157. Each of the spring followers F is provided with upper and lower lugs 15S extending oppomier-55e sitely froni the rectangular plate portion 15T in a direction lateral to the axis of the gear. The upper and lower lugs 158 are spaced apart vertically a proper distance to loosely receive therebetween the groups of friction plates, the elongated inner ends of the frio tion wcdgeishocs D and the tapering` frietion elein es E. the lugs 1,58 serve as a means for restoring the groups of friction plates l and the tapered friction elements E to norinal positiona the ends thereof engaging with shoulders 159 formed at theopposite ends of each of the tapered friction elements E and shoulders 127 on the frietion plates 125 and 1269 siniilar to the shoulders 27 of the preferred forni.

The spring resistance G comprises a relalivel),v heavy, outer coiled spring 1GO and relativelyv lighter7 inner coiled spring 161. lhe springs 15() and 161 are interposed between the spring followers F", the inner coiled spring 161 being held in centered position by the in fardly projecting bosses on the respective spring followers F.

lhe ineclianisin held under initial coniprcssion by the retainer boit lil anchored within the hollow bosses of the front :1nd rear follower casings A and extending Ilirough the inner coiled spring 161 and aline-d recesses in the front and rear spring followers le" and the front and rear wedge blocks C.

in the operation of the modified form of the iA eehanif-iin as shown in Figs. T and il, assuinin that the front follower A is being nioved toward the rear follower A during buff, a wedge action will be set up between the wedges C and the wedge shoes D causing pressure to be applied to the groups of friction plates at the opposite sides of the wedge friction shoes D will slide on the inner friction plates of each gri'iup of plates l i? the free ends of the fr plates are picked up by the follower and iove therewith in a manner similaito that described in connection with the preferred forni of the invention. During` the inward inoveinent of the follow Yr casing ing action wil also be set up between tue inner friction surfer-ee of the raeings il. and the taper friction elements lil herebv effecting bodily lateral movement of the groups of friction plates and the friction sli .:cs D. c lateral movement or i', wedge faces 5l of the shoes., on the wed faces 153 of the wedge blocks C. effects furtiicr compression of the spring resistance x. Upon removing the pressure freni the shoclr absorbing inechanisin7 the wedge locks C and shoes D together with the fdllowers will be caused to nieve outwardly first, bv the expansion of the springs 1G() an( 15h thus arising a. prompt release ofthe wenglll) ing mechanism and an immediate decrease of the pressure on the friction plates prior to any relative movement of the plates with reference to each other and with reference to the friction elements E. fis the spring followers move outwardly with the wedge friction shoes, the lugs 158 thereon will engage with the shoulders on the friction plates, thereby restoring the same to normal position with the free ends thereof slightly spaced from the end walls 11S of the corresponding follower casings A.

I have herein shown and described what I now consider' the preferred manner of carrying out my invention, but the same is merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

l. In a friction shock absorbing mechanism, the combination with oppositely arranged, hollow, front and rear follower casings provided respectively with forwardly and rearwardly converging friction surfaces on the interior thereof, said casings being normally spaced apart and adapted to move rela-tively to each other; of a. longitudinally arranged, wedge-actuated, lateral pressure creating means interposed between said followers; main spring resistance means; longitudinally arranged friction plates adapted for relative movement upon relative movement of the follower casings, said plates being divided into two groups on opposite sides of said wedge pressure creating means; and friction means interposed between each group of plates and adjacent friction surfaces of said casings.

2. In a friction shock absorbing mechanism, the combination with oppositely arranged, hollow, front and rear follower casings, provided with interior friction surfaces converging toward the opposite ends of the mechanism; of a longitudinally arranged, wedge pressure creating means coacting with said follower casings; main spring resistanco means; longitudinally arranged, co-acting` friction plates adapted to be moved relatively upon relative movement of the follower casings, said plates being divided into two groups on opposite sides of said wedge pressure creating means; and an oppositely tapering friction plate interposed between each group of plates and the adjacent friction surfaces of said casings.

8. In a friction shock absorbing mechanism, the combination with front and rear follower elements, each provided with oppositely disposed, longitudinally extending, friction surfaces, said surfaces being inclined with reference to the longitudinal axis of the mechanism of wedge pressure creating means interposed between said followers; main springresistance means; longitudinally arranged friction plates adapted for relative movement upon relative movement of said followers, said plates being divided into two groups on opposite sides of said wedge pressure creating means; and longitudinally arranged', oppositely tapering, elements interposed between each group of plates and adjacent friction surfaces of the followers.

l. In a friction shock absorbing mechanism, the combination with a plurality of groups of intercalated yfriction plates; of a wedge pressure creating means interposed between said groups of plates; main spring resistance means; a tapering friction element co-acting with each group of plates; and front and rear followers co-operating with said wedge pressure creating means,

and adapted to move said friction plates relatively to each other, each of said followers beingl provided with longitudinally arranged friction surfaces inclined with reference to the axis of the mechanism and co-acting with said tapering friction elements.

5. In a friction shock absorbing mechanism, the combination with a plurality of sets of relatively movable intercalated friction plates, divided into two groups; of a front follower casing co-act-ing with one set of plates and provided with forwardly converging friction surfaces on the interior thereof; a rear follower casing co-acting` with the other set of plates and provided with rearwardly converging friction surfaces on the interior thereof; a friction element interposed between each group of plates and the adjacent friction surfaces of said follower's, said element being provided with oppositely extending friction surfaces, one of said surfaces being arranged parallel to and co-acting with one of the friction surfaces on the front follower, and the other of said surfaces being arrzi-nged parallel to and co-acting with one of the friction surfaces of said rear follower; a wedge pressure creating means interposed between said groups of plates and adapted to be actua ted by the relative movement of the follower casings; and spring resistance means cooperating with said wedge pressure creatmg means.-

(i. In a Afriction shock absorbing mechanism, the combination with front and rear follower casings provided with oppositely arranged interior friction surfaces; of a longitudinally arranged wedge pressure creating means interposed between said followers and adapted to be actuated thereby; spring resistance means cooperating with said wedge pressure creating means; longitudinally arranged friction plates adapted for relative movement upon relative movement of the follower casings, said plates being divided into two groups on opposite sides of said wedge pressuie creating means; and a tapered friction element interposed llO between each group of plates and the adjacent friction surfaces of said follower casings; and provided with friction surfaces co-operating with said adjacent friction surfaces of the front and rear follower 'casings 7. In a friction shock absorbing mechanism, the combination with oppositely arranged, front and rear, follower casings provided with interior inclined friction surfaces, said casiiigs being normally spaced apart and adapted to move relatively; of wedge blocks movable with said follower casings; wedge elements co-operating with said wedge blocks; spring resistance co-operating with said wedge blocks; longitudinally arranged friction plates adapted for relative movement upon relative movement of the follower casiiigs; said plates being divided into two groups on opposite sides of said wedge pressure creating means; each group comprising two sets of plates; means arranged to engage each plate near one end thereof for restoring each set of plates to normal position with the opposite ends thereof slightly spaced from the adjacent follower; and a friction element having inclined friction surfaces interposed between each group of plates and the adjacent friction surfaces of said follower casings and having the inclined surfaces thereof co-operating with said inclined friction surfaces of the casings.

S. In a friction shock absorbing mechanism; the combination with oppositely arranged; front and rear, follower casings provided with interior friction surfaces7 said casings being normally spaced apart and adapted to move relatively; of lateral wedge pressure creating means co-operating with said followers; longitudinally arranged friction plates adapted for relative movement upon relative movement of the follower easings; said plates being divided into two groups on opposite sides of said wedge pressure creating means; each group coniprising two of plates; a tapering friction element interposed between each group of plates and the adjacent friction surfaces of said casings; means arranged to engage coriesponding ends of the friction plates of each set for restoring the saine to normal position; and co-acting means on said restoring means and plates for normally spacing the ends of said plates from the end walls of the respective follower casing to permit preliminary action of said followers and wedge pressure creating means prior .to engagement of the followers with the friction plates to actuatc the latter.

9. ln a friction shock absorbing mechanism, the combination with front .and rear, relatively movable followers provided with longitudinally arranged frictionl surfaces; of longitudinally arranged friction plates adapted for relative movement upon relative movement of said followers7 said plates being divided into two groups, each group comprising two sets of plates; a tapering friction clement interposed between each group of plates and the adjacent friction surfaces of said followers; and lateral wedge pressure creating means interposed between said two groups of plates and co-operating with said followers, said means including wedge elements, spring resistance means and spring followers; said spring followers being provided with means rigid therewith for engaging corresponding ends of the friction plates of each set for returning the same to normal position; said means including cooperating abutments on said plates and rigid means for normally slightly spacing the engaged ends of the plates of cach set from the ad iacent followers to permit preliminary action of said followers and wedge pressure creating means prior to engagement of the followers with tlie friction plates to actuate the latter.

l0. In a friction shock absorbing mechanism, the combination with a plurality of sets of relatively movable intercalated friction plates; divided into two groups; of a front follower casing co-acting with one set of plates, said casing being provided with longitudinally arranged interior friction surfaces; a rear follower' casing cci-acting with the other set of plates, said casing being provided with longitudinally arranged interior frictional surfaces; a friction element interposed between each group of plates and the adjacent friction faces of said followers; and a lateial pressure creating means interposed between said groups of plates, said lateral pressure creating means including wedge blocks movable with said followers7 central wedges having fiat faces engaging the inner sides of the groups of plates, additional wedges co-acting with said first named wedges and said central wedges, and tandem arranged springs co-acting with said additional wedges.

ll. In a friction shock absorbing mechanism; the combination with a plurality of sets of relatively movable intercalated friction plates; divided into two groups; of a front follower casing co-acting with one set of plates;` said casing being provided with longitudinally arranged interior friction surfaces; a rear follower casing co-acting with the other set of plates, said casing being provided with longitudinally arranged interior friction surfaces; a friction element interposed between each group of plates and the adjacent friction surface of said followers; and a lateral pressure creating means interposed between said groups of plates; said lateral pressure crea-ting means including wed-ges movable with said followers, a central wedge anchored to each friction element and provided with a fiat face engaging the inner side of the adjacent group of friction plates, additional wedges co-acting with said first named wedges and said central wedges and tandem arranged springs coacting with said additional wedges.

l2. ln a friction shock absorbing mechanism, the combination with a plurality of sets of relatively movable intercalated friction plates, divided into two groups, of a front follower casing co-acting with one set of plates, said casing being provided with longitudinally arranged interior friction surfaces; a rear follower casing co-acting with the other set of plates, said casing being provided with longitudinally arranged interior friction surfaces; a friction element .interposed between each group of plates and the adjacent friction surfaces of said followers; a pair of wedge blocks movable with each follower, each of said wedge blocks having a flat face co-acting with the inner side of one of said groups of friction plates; a pair of central wedges each having a pair of wedge faces and a fiat face, said flat face co-acting with one of said groups of friction plates; a pair of combined wedge and spring followers eo-acting with said central wedges; a combined wedge and spring follower co-acting with each pair of wedge blocks; and a spring resistance co-acting with said combined wedges and spring followers.

13. In a friction shock absorbing mechanism, the combination with oppositely arranged, front and rear, follower casings provided with interior friction surfaces, said casings being normally spaced apart and adapted to move relatively; of a wedge pressure creating means interposed between said follower casings, said means including wedge blocks co-act-ing with the front and rear follower casings respectively, tandem arranged springs, con tral wedges between the adjacent ends of said springs, a combined wedge and spring follower' interposed between the central .vedges and the adjacent end of each spring, an outer combined wedge and spring follower interposed between the springs and wedge blocks coacting with the front follower, and an outer combined wedge spring` follower interposed between the springs and the wedge blocks co-acting with the rear follower; longitudinally arranged sets of friction plates adapted foiwrelative movement upon relative movement of said follower casings, said plates being arranged in two groups on opposite sides of said wedge pressure creating means; a friction element interposed between each group of friction plates and the adjacent friction surfaces of said follower casings; and interengaging means on corresponding ends of one set of friction plates and one of said outer combined wedges and spring followers, and on corresponding ends of the other of said sets of friction plates and the other outer combined wedge and spring follower for restoring `the friction plates to normal position.

le. ln a friction shock absorbing mechanism, the combination with front and rear follower members adapted to move relatively toward and .from each other; of a group of longitudinally extending intercalated friotion plates interposed between said follower members and adapted to be shifted longitudinally relatively to each other upon relative approach of said follower members, said group of plates being responsive to laterally applied pressure; and` means for compressmg said groups of plates laterally, said means being operative upon relative approach of said follower members, said means including a spring resistance, and means operative upon relative approach of said follower members, to shift said group of plates bodily transverse to the line of relative approach of said follower members.

l5. In a shock absorbing mechanism, the combination with front and rear follower members adapted to move toward and from each other; two, laterally separated, groups of longitudinally extending, intercalated friction plates adapted for relative longitudinal movement upon relative approach of said follower members, said plates being responsive to laterally applied pressure thereon; and means for compressing said groups of plates laterally upon relative approach of the follower members and including a longitudinally arranged spring resistance located between the groups of plates, and means operative to shift the two groups of plates bodily transverse to the line of relative approach of the follower members when the latter are moved relatively toward each other.

1G. In a friction shock absorbing mechanism, the combination with a plurality of intercalated, relatively movable, longitudinally disposed group of friction plates; means for placing said plates under lateral pressure, including wedge friction shoes at the opposite ends of said plates and engaging said group of plates on one side thereof, spring resistance means opposing relative movement of the shoes at the opposite ends of the plates, spring followers co-operating with said spring resistance and shoes, said followers having means thereon engaging said plates for returning them to normal position, relatively movable main followers having engagement with said shoes for effecting longitudinal movement of the latter, and lateral movement resisting means movable with said main followers disposed on the other side of said group of plates and having laterally acting inclined faces.

17. In a draft gear, in combination, a pair of chambered followers, the side walls of each being tapered, a set of centrally disposed Wedging` elements in each follower', interealatinagplates at eaeli side of the wedging elements, means including niembers engaging said Wedging elements for creating lateral pressure on said plates during` Compression of said gear, and a tapered plate interposed between the plates and the side walls of both followers.

18. In a draft gear, a pair of Jfollowers bowing` inclined inner side walls, interealated friction plates including a plate having eorreeponding inclined surfaces for engaging the inclined surfaces of said followers, and means for Creating;` lateral pressure on said plates and for causing relative movement of the saine during the compression of said gear.

In Witness that I claim the foregoing` I have hereunto subscribed niy name this` 2nd day of February, 1923.

JOHN F. OCONNOR. 

